The pattern of synthesis of outer and inner membrane proteins is being analyzed during the cell division cycle of E. coli B/r at various growth rates. Nutritional shifts of slowly growing populations will be used to determine whether the synthetic rates of the envelope proteins change in correspondence of septation and/or division or in parallel with initiation of new rounds of chromosome replication. Envelope proteins will be tested for DNA binding ability. Envelope proteins of pairs of exponential phase populations growing at two different growth rates and radioactively labeled with the same amino acid, one with 3H and the other with 35S, will be isolated from a mixture of the two cultures. For DNA binding, both single and double stranded E. coli DNA will be used. The ratio 3H/35S of the samples eluted at high salt concentration will be compared to the ration of the proteins in the wash. Difference in these ratios would be indicative of differential binding at the various growth rates. The degree of affinity will be analyzed based on the composition of the outer membrane, and the number of chromosomal origins and termini in the cells. Binding to DNA of envelope components during the cell cycle and during nutritional shift of synchronous populations will be determined.